What does an increase in Serum Glutamic-Oxaloacetic Transaminase (SGOT) and Serum Glutamic-Pyruvic Transaminase (SGPT) levels with fever indicate?

Elevated SGOT and SGPT with Fever: Diagnostic Implications

Elevated SGOT (AST) and SGPT (ALT) levels in the presence of fever most commonly indicate liver involvement due to infectious causes, with viral hepatitis, typhoid fever, dengue fever, and Adult-Onset Still's Disease being the most significant considerations.

Common Infectious Causes

• Viral Hepatitis: Causes significant elevation of liver enzymes, with AST/ALT ratio typically <1 in acute viral hepatitis. In viral hepatitis, AST and ALT levels may rise to more than 10 times the upper limit of normal 1.

• Typhoid Fever: Presents with hepatomegaly (51.6%), elevated SGOT (61.3%), and elevated SGPT (48.4%). These abnormalities are transient and return to normal within 2-3 weeks after successful antibiotic therapy 2.

• Dengue Fever: Associated with abnormal AST and ALT levels in 93.3% and 82.2% of patients respectively. Initially, AST levels are typically higher than ALT, with maximum elevation occurring around nine days after symptom onset 1.

• Scrub Typhus: Causes elevation of SGOT and SGPT in 80% and 70% of septic patients respectively, often accompanied by elevated alkaline phosphatase (80%) and direct bilirubin (95%) 3.

Non-Infectious Causes

• Alcoholic Liver Disease: Characterized by an SGOT/SGPT ratio >2, which is highly suggestive of alcoholic hepatitis and cirrhosis. This ratio occurs in 70% of patients with alcoholic liver disease compared to much lower percentages in other liver conditions 4.

• Adult-Onset Still's Disease (AOSD): Features liver abnormalities in 50-75% of patients, including hepatomegaly and abnormal liver biochemistry. AOSD should be considered when fever is accompanied by characteristic rash, arthralgia, and very high ferritin levels 5.

Diagnostic Approach

Initial Evaluation

• Obtain detailed history focusing on:

  • Recent travel (for tropical diseases like dengue) 6
  • Alcohol consumption (for alcoholic liver disease) 4
  • Drug exposures (for drug-induced liver injury) 6
  • Joint pain and rash (for AOSD) 5

• Physical examination should focus on:

  • Presence of hepatomegaly 5, 2
  • Jaundice 3
  • Characteristic rashes (e.g., salmon-colored rash in AOSD) 5
  • Joint involvement 5

Laboratory Testing

• Complete blood count: Look for leukocytosis with neutrophilia (common in AOSD and bacterial infections) 5

• Inflammatory markers: Check ESR and CRP, which are typically elevated in infectious and inflammatory conditions 5

• Liver function tests:

  • Calculate the AST/ALT ratio (>2 suggests alcoholic liver disease) 4
  • Check alkaline phosphatase and bilirubin levels 3

• Specific tests based on clinical suspicion:

  • Ferritin levels (extremely high in AOSD, often >5000 ng/ml) 5
  • Blood cultures (for typhoid fever and other bacterial infections) 2
  • Serological tests for viral hepatitis 1
  • Procalcitonin (to help distinguish bacterial from non-bacterial causes) 7

Imaging

• Abdominal ultrasound to evaluate for hepatomegaly, splenomegaly, and other abnormalities 6

Special Considerations

• Pattern of enzyme elevation: The AST/ALT ratio can help distinguish between different etiologies:

  • Ratio >2: Suggests alcoholic liver disease 4
  • Ratio <1: Common in viral hepatitis 1

• Degree of elevation:

  • Mild to moderate elevation (2-10 times normal): Seen in many infections including typhoid fever 2
  • Marked elevation (>10 times normal): More common in acute viral hepatitis, drug-induced liver injury, and ischemic hepatitis 1

• Associated symptoms:

  • Persistent high-spiking fever with rash and arthralgia suggests AOSD 5
  • Fever with gastrointestinal symptoms may indicate typhoid or dengue 2, 1

Pitfalls to Avoid

• Do not assume that elevated liver enzymes with fever always indicate primary liver disease, as they can be part of systemic infections or inflammatory conditions 6

• Remember that liver enzyme abnormalities in typhoid fever can occur even without hepatomegaly 2

• Do not overlook AOSD in young adults with persistent fever, as it is an important cause of fever of unknown origin with liver enzyme abnormalities 5